package cn.lccabc.dichotomy.no0034;

/**
 * 给定一个按照升序排列的整数数组 nums，和一个目标值 target。找出给定目标值在数组中的开始位置和结束位置。
 *
 * 你的算法时间复杂度必须是 O(log n) 级别。
 *
 * 如果数组中不存在目标值，返回 [-1, -1]。
 *
 * 示例 1:
 *
 * 输入: nums = [5,7,7,8,8,10], target = 8
 * 输出: [3,4]
 * 示例 2:
 *
 * 输入: nums = [5,7,7,8,8,10], target = 6
 * 输出: [-1,-1]
 *
 */
public class Solution {

    public static int[] searchRange(int[] nums, int target) {
        if (nums.length == 0) return new int[]{-1, -1};
        int left = 0, right = nums.length - 1;
        while (left + 1 < right){
            int mid = left + (right - left) / 2;
            if (nums[mid] <= target){
                left = mid;
            } else {
                right = mid;
            }
        }
        int index = -1;
        // [2,2] target = 2 right先检测
        if (nums[right] == target){
            index = right;
        } else if (nums[left] == target){
            index = left;
        }
        if (index != -1){
            int start = index;
            // 越界 -1
            while (--start >= 0 && nums[start] == target);
            return new int[]{start + 1, index};
        } else {
            return new int[]{-1, -1};
        }
    }


    public static void main(String[] args) {
        int[] nums = new int[]{2,2};
        int target = 2;
        int[] result = searchRange(nums, target);
        System.out.println(result[0] + " <-> " + result[1]);
    }
}
